Admin UI ng fails mvn clean install if the node_modules exists

Steps to reproduce:
1. cd in to modules/matterhorn-admin-ui-ng and run "mvn clean install"
2. After it builds successfully, run "mvn clean install" again

Actual Results: BUILD FAILURE
Message "TypeError: Cannot read property '0' of undefined" at rmStuff method inside matterhorn-admin-ui-ng/node/node_modules/npm/lib/unbuild.js:63:24

Expected Results: BUILD SUCCESS on each mvn clean install even if
the node_modules exists.

Workaround (if any):
Delete the admin-ng's node_modules before each mvn clean install and wait for npm 5.3.0 to get a fix for https://github.com/npm/npm/issues/17858
Other project teams have downgraded to npm 5.2.0 because of this issue.